Battery cell, battery pack and electrical device

Abstract

The present application discloses a battery cell, a battery pack and an electrical device. The battery cell includes: a housing having an opening at one end; an electrolyte disposed in the housing; a cell assembly including a cell body disposed in the housing and a tab connected to the cell body and located at one end of the cell body close to the opening of the housing; a plastic part covering the opening of the housing to form a receiving cavity for receiving the electrolyte and the cell assembly together with the housing, the plastic part including a plate-shaped part covering the opening of the housing and a protruding part provided on the inner surface of the plate-shaped part facing the housing; a first liquid-absorbing member extending from the plastic part towards the cell body, and the distance between the end of the first liquid-absorbing member away from the cell body and the cell body is equal to or greater than the distance between the inner surface of the plate-shaped part and the cell body.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery pack and an electrical device. Background Art

[0002] Battery cells are widely used in electronic devices, such as mobile phones, laptop computers, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc. Battery cells can include nickel-cadmium battery cells, nickel-hydrogen battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells, etc. In the development of battery technology, how to improve the reliability of battery cells is a technical problem that needs to be solved in battery technology. Summary of the invention

[0003] The present application aims to provide a battery cell, a battery pack and an electrical device that are beneficial to improving the reliability of the battery cell.

[0004] According to one aspect of the present application, a battery cell is provided, which includes: a shell having an opening at one end; an electrolyte disposed in the shell; a battery cell assembly, including a battery cell body disposed in the shell and a pole ear connected to the battery cell body and located at one end of the battery cell body close to the opening of the shell; a plastic part, which covers the opening of the shell to form a accommodating chamber for accommodating the electrolyte and the battery cell assembly with the shell, the plastic part including a plate-like part covering the opening of the shell and a protruding part disposed on the inner surface of the plate-like part facing the shell; and a first liquid absorbing part extending from the plastic part toward the battery cell body, the distance between the end of the first liquid absorbing part away from the battery cell body and the battery cell body being equal to or greater than the distance between the inner surface of the plate-like part and the battery cell body.

[0005] In some embodiments, the plastic part includes a through hole allowing an electrode terminal connected to the tab to pass through, the two through holes are arranged along a first direction and are respectively located at two ends of the plastic part along the first direction, and the first liquid absorbing member is provided at the end of the plastic part along the first direction.

[0006] In some embodiments, the protrusion is provided with an embedding groove connected to the accommodating cavity, the embedding groove extends from one end of the protrusion close to the battery cell body to the plate-like portion, the depth of the embedding groove is greater than or equal to the height of the protrusion protruding from the plate-like portion, and the first liquid absorbent member is embedded in the embedding groove.

[0007] In some embodiments, the battery cell further comprises an end cover disposed on a side of the plastic part away from the battery cell assembly, and the embedding groove extends to a side of the plastic part facing the end cover.

[0008] In some embodiments, the first liquid absorbent member includes an embedded portion filled in the groove and a stacked portion connected to the embedded portion and stacked between the end face of the protruding portion facing the battery cell main body and the battery cell main body. The stacked portion covers one end of the embedded portion close to the battery cell main body and the end face of part or all of the protruding portion close to the battery cell main body.

[0009] In some embodiments, the first liquid absorbent member includes an attached portion attached to the inner surface of the plate-shaped portion.

[0010] In some embodiments, the first liquid absorbent member further includes a stacked portion connected to the attached portion and stacked between the end face of the protruding portion facing the battery cell main body and the battery cell main body. The stacked portion covers the end face of part or all of the protruding portion close to the battery cell main body.

[0011] In some embodiments, the first liquid absorbent member further includes a connecting portion connecting the attached portion and the stacked portion. The connecting portion is attached to the side surface of the protruding portion.

[0012] In some embodiments, the attached portion extends from the protruding portion toward the through hole in the plate-shaped portion through which the electrode terminal allowed to be connected to the tab can pass.

[0013] In some embodiments, the tab is bent from one side of the end face of one end of the battery cell main body close to the plastic part toward the middle. The battery cell unit further includes a connecting member covering the side of the bent tab away from the battery cell main body and connected to the tab, and an electrode terminal connected to the connecting member. The first end of the first liquid absorbent member is attached to the side of the connecting member away from the tab and extends along the side of the bent tab facing away from the battery cell main body toward the battery cell main body.

[0014] In some embodiments, the second end of the first liquid absorbent member away from the connecting member is attached to the side surface of the battery cell main body.

[0015] In some embodiments, the plastic part covers the side of the connecting member away from the battery cell assembly, and the side of the first liquid absorbent member away from the connecting member is attached to the inner surface of the plate-shaped portion.

[0016] In some embodiments, the battery cell unit further includes a second liquid absorbent member. The first end of the second liquid absorbent member is attached to the side of the bent tab facing the battery cell main body and extends along the tab toward the side of the battery cell main body facing the plastic part.

[0017] In some embodiments, two battery cell assemblies are arranged side by side, and the tabs of the two battery cell assemblies are respectively bent toward the junction of the two battery cell assemblies. Both sides of the connecting member are respectively connected to the tabs of the two battery cell assemblies.

[0018] In some embodiments, the second liquid absorbent member extends to the side surface of the battery cell main body, and the second end of the second liquid absorbent member away from the tab is attached to the side surface of the battery cell main body.

[0019] In some embodiments, one end of the first liquid-absorbing member away from the plate-shaped portion abuts against or is connected to the main body of the battery cell.

[0020] According to another aspect of the present application, there is also provided a battery pack, which includes the above-mentioned battery cell.

[0021] According to another aspect of the present application, there is also provided an electrical device, which includes the above-mentioned battery pack.

[0022] Applying the technical solution of the present application, after the battery cell is inverted, one end of the first liquid-absorbing member away from the main body of the battery cell is not higher than the inner surface of the plate-shaped portion of the plastic part, so as to guide the electrolyte flowing onto the inner surface of the plate-shaped portion upward through capillary action, which is beneficial to improving the problem that the electrolyte flows to a position closer to the end cap, corroding the weak area of the end cap, resulting in a reduction in the reliability of the battery cell, and is also beneficial to ensuring the mechanical strength of the battery end cap.

[0023] Through the following detailed description of the exemplary embodiments of the present application with reference to the accompanying drawings, other features and advantages of the present application will become clear. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 The structural schematic diagram of an electrical device disclosed in some embodiments of the present application is shown.

[0026] Figure 2 The exploded structural schematic diagram of a battery pack disclosed in some embodiments of the present application is shown.

[0027] Figure 3 The exploded structural schematic diagram of a battery cell disclosed in some embodiments of the present application is shown.

[0028] Figure 4 The structural schematic diagram of a battery cell disclosed in some embodiments of the present application is shown.

[0029] Figure 5 The side view structural schematic diagram of a battery cell disclosed in some embodiments of the present application is shown.

[0030] Figure 6 The structural schematic diagram of the housing and the battery cell assembly of a battery cell disclosed in some embodiments of the present application is shown.

[0031] Figure 7 Shows a bottom view structural schematic diagram of a plastic part and a first liquid absorption part of a battery cell disclosed in some embodiments of the present application.

[0032] Figure 8 Shows a side view structural schematic diagram of a plastic part and a first liquid absorption part of a battery cell disclosed in some embodiments of the present application.

[0033] Figure 9 Shows a structural schematic diagram of an end cap of a battery cell disclosed in some embodiments of the present application.

[0034] Figure 10 Shows a structural schematic diagram of a battery cell disclosed in some embodiments of the present application.

[0035] Figure 11 Shows a side view structural schematic diagram of a battery cell disclosed in some embodiments of the present application.

[0036] Figure 12 Shows a structural schematic diagram of a housing and a battery core assembly of a battery cell disclosed in some embodiments of the present application.

[0037] Figure 13 Shows a bottom view structural schematic diagram of a plastic part and a first liquid absorption part of a battery cell disclosed in some embodiments of the present application.

[0038] Figure 14 Shows a side view structural schematic diagram of a plastic part and a first liquid absorption part of a battery cell disclosed in some embodiments of the present application.

[0039] Figure 15 Shows a structural schematic diagram of an end cap of a battery cell disclosed in some embodiments of the present application.

[0040] Figure 16 Shows a structural schematic diagram of a battery cell disclosed in some embodiments of the present application.

[0041] Figure 17 Shows a side view structural schematic diagram of a battery cell disclosed in some embodiments of the present application.

[0042] Figure 18 Shows a structural schematic diagram of a housing and a battery core assembly of a battery cell disclosed in some embodiments of the present application.

[0043] Figure 19 Shows a bottom view structural schematic diagram of a plastic part and a first liquid absorption part of a battery cell disclosed in some embodiments of the present application.

[0044] Figure 20Shows a schematic side view structure of a plastic part and a first liquid absorption part of a battery cell disclosed in some embodiments of the present application.

[0045] Figure 21 Shows a schematic structure diagram of an end cap of a battery cell disclosed in some embodiments of the present application.

[0046] Figure 22 Shows a schematic structure diagram of a battery cell disclosed in some embodiments of the present application.

[0047] Figure 23 Shows Figure 22 A schematic cross-sectional structure diagram at A-A in

[0048] Figure 24 Shows a schematic cross-sectional structure diagram of a battery cell disclosed in some other embodiments of the present application.

[0049] Figure 25 Shows a schematic structure diagram of a housing and a battery cell assembly of a battery cell disclosed in some embodiments of the present application.

[0050] Figure 26 Shows a schematic structure diagram of a first state of the assembly process of a battery cell disclosed in some embodiments of the present application.

[0051] Figure 27 Shows a schematic side view structure of a first state of the assembly process of a battery cell disclosed in some embodiments of the present application.

[0052] Figure 28 Shows Figure 27 A partial enlarged view at B in

[0053] Figure 29 Shows a schematic structure diagram of a second state of the assembly process of a battery cell disclosed in some embodiments of the present application.

[0054] Figure 30 Shows a schematic structure diagram of a third state of the assembly process of a battery cell disclosed in some embodiments of the present application.

[0055] In the figure: 1000, vehicle; 100, battery pack; 110, box body; 111, first part; 112, second part; 120, battery cell; 121, end cover; 121a, electrode terminal; 122, housing; 123, cell assembly; 123a, tab; 123b, cell main body; 124, plastic part; 1241, plate-like part; 1242, protruding part; 1243, through hole; 125, first liquid absorbent; 1251, embedded part; 1252, stacked part; 1253, attached part; 1254, connecting part; 126, second liquid absorbent; 127, connecting piece; 200, controller; 300, motor. Detailed implementation manners

[0056] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0057] In the description of the present application, it should be noted that unless otherwise specified, the meaning of "a plurality" is two or more; the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0058] The orientation words appearing in the following description are all the directions shown in the figure and do not limit the specific structure of the present application. In the description of the present application, it should also be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0059] Further, the "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include the end values or not include the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, ranges of 60-110 and 80-120 are also contemplated. In addition, if the minimum range values of 1 and 2 are listed, and if the maximum range values of 3, 4, and 5 are listed, the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise specified, the numerical range "a-b" represents an abbreviated representation of any real number combination between a and b, where both a and b are real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" are fully listed herein, and "0-5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0060] If there is no special instruction, all embodiments and optional embodiments of this application can be combined with each other to form a new technical solution.

[0061] If there is no special instruction, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0062] If there is no special instruction, all steps of this application can be carried out in sequence or randomly, and preferably in sequence. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out in sequence, or can also include steps (b) and (a) carried out in sequence. For example, it is mentioned that the method may further include step (c), which means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c), or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0063] If there is no special instruction, the "including" and "comprising" mentioned in this application mean open-ended or can also be closed-ended. For example, the "including" and "comprising" can mean that other components not listed can also be included or comprised, or can also only include or comprise the listed components.

[0064] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, any of the following conditions satisfies the condition "A or B": A is true (or present) and B is false (or absent); A is false (or absent) while B is true (or present); or both A and B are true (or present).

[0065] Currently, from the perspective of the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric transportation such as electric bicycles, electric motorcycles, and electric vehicles, as well as in many fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also constantly increasing.

[0066] Figure 1 The structural schematic diagram of an electric device using a battery as a power source is shown; as Figure 1 shown, the electric device of this embodiment includes a vehicle 1000, and the vehicle 1000 can be a pure electric vehicle, a hybrid vehicle, an extended-range vehicle, etc. A battery pack 100 is arranged inside the vehicle 1000, and the battery pack 100 can be arranged at the bottom, head, or tail of the vehicle 1000. The battery pack 100 can be used to supply power to the vehicle 1000. For example, the battery pack 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery pack 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1000.

[0067] In some embodiments of this application, the battery pack 100 can not only be used as the operating power source of the vehicle 1000, but also as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0068] Please refer to Figure 2 , Figure 2Explosion diagram of the battery pack 100 provided by some embodiments of the present application. The battery pack 100 includes a box body 110 and a battery module disposed within the box body 110. The battery module includes a plurality of battery cells 120, and the battery cells 120 are accommodated within the box body 110. Among them, the box body 110 is used to provide an accommodation space for the battery cells 120, and the box body 110 can adopt various structures. In some embodiments, the box body 110 may include a first part 111 and a second part 112. The first part 111 and the second part 112 cover each other, and the first part 111 and the second part 112 jointly define an accommodation space for accommodating the battery cells 120. The second part 112 may be a hollow structure with one end open, and the first part 111 may be a plate-like structure. The first part 111 covers the open side of the second part 112 so that the first part 111 and the second part 112 jointly define an accommodation space; the first part 111 and the second part 112 may also both be hollow structures with one side open, and the open side of the first part 111 covers the open side of the second part 112. Of course, the box body 110 formed by the first part 111 and the second part 112 can be of various shapes, such as a cylinder, a cuboid, etc.

[0069] In the battery pack 100, there may be a plurality of battery cells 120. The plurality of battery cells 120 can be connected in series, in parallel, or in a mixed connection. A mixed connection means that there are both series and parallel connections among the plurality of battery cells 120. The plurality of battery cells 120 can be directly connected in series, in parallel, or in a mixed connection together, and then the whole formed by the plurality of battery cells 120 is accommodated within the box body 110; of course, the battery pack 100 can also be that a plurality of battery cells 120 are first connected in series, in parallel, or in a mixed connection to form a battery module form, and then a plurality of battery modules are connected in series, in parallel, or in a mixed connection to form a whole and are accommodated within the box body 110. The battery pack 100 may further include other structures. For example, the battery pack 100 may further include a busbar component for realizing electrical connection among the plurality of battery cells 120.

[0070] Among them, each battery cell 120 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 120 can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc.

[0071] Please refer to Figure 3 , Figure 3 Schematic exploded view of the battery cell 120 provided by some embodiments of the present application. The battery cell 120 refers to the smallest unit that makes up the battery pack 100. As Figure 3 shown, the battery cell 120 includes an end cap 121, a housing 122, a core component 123, and other functional components.

[0072] The end cap 121 refers to a component that covers the opening of the housing 122 to isolate the internal environment of the battery cell 120 from the external environment. Without limitation, the shape of the end cap 121 can be adapted to the shape of the housing 122 to fit the housing 122. Optionally, the end cap 121 can be made of a material with a certain hardness and strength, such as aluminum alloy. In this way, the end cap 121 is not easily deformed when subjected to extrusion and collision, enabling the battery cell 120 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 121a can be provided on the end cap 121. The electrode terminal 121a can be used for electrically connecting to the battery cell assembly 123 to output or input the electrical energy of the battery cell 120. In some embodiments, a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 120 reaches a threshold can also be provided on the end cap 121. The material of the end cap 121 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this. In some embodiments, an insulating member can also be provided on the inner side of the end cap 121, and the insulating member can be used to isolate the electrical connection components in the housing 122 from the end cap 121 to reduce the risk of short circuit. Exemplarily, the insulating member can be plastic, rubber, etc.

[0073] The housing 122 is a component for cooperating with the end cap 121 to form the internal environment of the battery cell 120, wherein the formed internal environment can be used to accommodate the battery cell assembly 123, electrolyte, and other components. The housing 122 and the end cap 121 can be independent components. An opening can be provided on the housing 122, and the end cap 121 is covered on the opening to form the internal environment of the battery cell 120. Without limitation, the end cap 121 and the housing 122 can also be integrated. Specifically, the end cap 121 and the housing 122 can first form a common connection surface before other components are inserted into the housing, and when it is necessary to encapsulate the inside of the housing 122, the end cap 121 is then covered on the housing 122. The housing 122 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 122 can be determined according to the specific shape and size of the battery cell assembly 123. The material of the housing 122 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this.

[0074] The battery cell assembly 123 is a component in the battery cell 120 where an electrochemical reaction occurs. The housing 122 can contain one or more battery cell assemblies 123. The battery cell assembly 123 is mainly formed by winding or stacking electrode sheets, wherein the electrode sheets include positive electrode sheets and negative electrode sheets, and generally an isolation film is provided between the positive electrode sheet and the negative electrode sheet.

[0075] The electrode plate mainly consists of a flaky current collector and the active material coated on the current collector. The parts of the positive electrode plate, the negative electrode plate, the cathode electrode plate, and the anode electrode plate with the active material constitute the main body of the battery cell assembly, and the parts of the positive electrode plate and the negative electrode plate without the active material respectively constitute the electrode tabs 123a. The positive electrode tab and the negative electrode tab can be located at one end of the main body together or at both ends of the main body respectively. During the charging and discharging process of the battery pack 100, the positive active material and the negative active material react with the electrolyte, and the electrode tab 123a is connected to the electrode terminal to form a current loop.

[0076] In the placement state of a general battery cell, the opening of the housing 122 of the battery cell 120 faces upward, the end cap 121 covers the opening of the housing 122, the battery cell assembly 123 is accommodated in the accommodation cavity of the housing 122, and the electrode terminal 121a is connected to the electrode tab 123a of the battery cell assembly 123, passes through the end cap 121, and extends above the end cap 121.

[0077] In some cases, the battery cell 120 needs to be inverted. In the inverted state of the battery cell 120, the end cap 121 is located below the housing 122, and the opening of the housing 122 faces downward. After the battery cell is inverted, the electrolyte inside the battery cell will flow along the battery cell assembly 123 to a position closer to the end cap 121, corroding the weak areas of the end cap 121, such as the explosion-proof valve at the position of the end cap 121, the area near the electrode terminal 121a, and the weld area. The corrosion of the end cap 121 by the electrolyte will weaken the mechanical strength of the end cap 121, seriously affecting the reliability of the battery cell. In addition, the superimposed corrosion will continuously consume the electrolyte, and the effective electrolyte in the battery cell will become less and less. During the use of the battery cell, due to the aggravation of poor electrolyte infiltration, the cycle performance of the battery cell becomes worse.

[0078] To improve the above problems, the present application provides a battery cell. Refer to Figures 4 to 7 In some embodiments of the present application, the battery cell includes a housing 122, an electrolyte, a battery cell assembly 123, a plastic part 124, and a first liquid-absorbing part 125.

[0079] One end of the housing 122 is provided with an opening. The electrolyte is arranged in the housing 122. The battery cell assembly 123 includes a battery cell main body 123b arranged in the housing 122 and an electrode tab 123a connected to the battery cell main body 123b and located at one end of the battery cell main body 123b close to the opening of the housing 122. The plastic part 124 covers the opening of the housing 122 to form an accommodation cavity for accommodating the electrolyte and the battery cell assembly 123 with the housing 122. The plastic part 124 includes a plate-shaped part 1241 covering the opening of the housing 122 and a protruding part 1242 arranged on the inner surface of the plate-shaped part 1241 facing the housing 122.

[0080] The first liquid-absorbing member 125 extends from the plate-shaped portion 1241 toward the battery cell main body 123b, and the distance between the end of the first liquid-absorbing member 125 away from the battery cell main body 123b and the battery cell main body 123b is equal to or greater than the distance between the inner surface of the plate-shaped portion 1241 and the battery cell main body 123b.

[0081] Therefore, after the battery cell 120 is inverted, the end of the first liquid-absorbing member 125 away from the battery cell main body 123b is not higher than the inner surface of the plate-shaped portion 1241 of the plastic part 124, so as to guide the electrolyte flowing onto the inner surface of the plate-shaped portion 1241 upward by capillary action, which is beneficial to improving the problem that the electrolyte flows to a position closer to the end cap 121 and corrodes the weak area of the end cap 121, resulting in a reduction in the reliability of the battery cell 120, and is also beneficial to ensuring the mechanical strength of the battery end cap 121.

[0082] The first liquid-absorbing member 125 extends from the plate-shaped portion 1241 toward the battery cell main body 123b and is connected to and abuts against the battery cell main body 123b. After the battery is inverted, the electrolyte flowing to the plate-shaped portion 1241 of the plastic part 124 can be absorbed by the first liquid-absorbing member 125 under capillary action and the electrolyte is conveyed toward the battery cell main body 123b, thereby improving the problem of poor cycle performance of the battery cell 120 caused by the reduction of the electrolyte.

[0083] The material of the liquid-absorbing member is preferably a fibrous material, and the material can be selected from common high liquid-absorbing materials such as polyethylene oxide (PEO), polyacrylamide (PAM), and polyvinyl alcohol (PVA).

[0084] In some embodiments, the first liquid-absorbing member 125 is connected to or abuts against one end of the accommodating cavity close to the plate-shaped portion 1241 of the plastic part 124, so that the distance between the end of the first liquid-absorbing member 125 away from the battery cell main body 123b and the battery cell main body 123b is equal to the distance between the inner surface of the plate-shaped portion 1241 and the battery cell main body 123b, so that the first liquid-absorbing member 125 absorbs the electrolyte above the plate-shaped portion 1241 of the inverted battery cell 120, which is beneficial to preventing the problem of electrolyte remaining on the plate-shaped portion 1241.

[0085] In some other embodiments, the distance between one end of the first liquid-absorbing member 125 of the plastic part 124 away from the battery cell main body 123b is greater than the distance between the inner surface of the plate-shaped portion 1241 and the battery cell main body 123b. Specifically, a recessed portion is provided on the inner surface of the plate-shaped portion 1241, and one end of the first liquid-absorbing member 125 away from the battery cell main body 123b is embedded in the recessed portion. The electrolyte of the inverted battery cell 120 flowing towards the plate-shaped portion 1241 can converge towards the above-mentioned recessed portion and be guided towards the battery cell monomer through the capillary action of the first liquid-absorbing member 125, thereby improving the problem of the reduction in the reliability of the battery cell 120 caused by the corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 caused by the reduction of the electrolyte.

[0086] In some embodiments, the plastic part 124 includes through holes 1243 allowing the electrode terminals 121a connected to the electrode tabs 123a to pass through. The two through holes 1243 are arranged in a first direction and are respectively located at both ends of the plastic part 124 along the first direction. The first liquid-absorbing member 125 is provided at the end of the plastic part 124 along the first direction. Specifically, the two through holes 1243 are respectively located inside the protruding portions 1242 provided at both ends of the plate-shaped portion 1241 along the first direction.

[0087] The first liquid-absorbing member 125 is arranged near the electrode terminal to guide the electrolyte near the electrode terminal 121a towards the battery cell main body 123b, which is beneficial to preventing the corrosion of the welding part of the electrode terminal 121a by the electrolyte. Further, the problem of the reduction in the reliability of the battery cell 120 caused by the corrosion of the end cap of the battery cell 120 by the electrolyte and the problem of poor cycle performance of the battery cell 120 caused by the reduction of the electrolyte are improved.

[0088] In some embodiments, refer to Figure 5As for 7 and 8, the protruding part 1242 is provided with a groove connected to the accommodating cavity. The groove extends from one end of the protruding part 1242 close to the battery cell main body 123b towards the plate-shaped part 1241. The depth of the groove is greater than or equal to the height of the protruding part 1242 protruding from the plate-shaped part 1241. At least part of the first liquid absorbing member 125 is embedded in the groove. The distance between one end of the first liquid absorbing member 125 facing the bottom of the groove and the battery cell main body 123b is greater than or equal to the distance between the inner surface of the plate-shaped part 1241 and the battery cell main body 123b. That is, when the battery module is inverted, the end of the first liquid absorbing member 125 far from the battery cell main body 123b is lower than or flush with the inner surface of the plate-shaped part 1241, which is beneficial for the first liquid absorbing member 125 to guide the electrolyte flowing towards the plate-shaped part 1241 to the battery cell main body 123b under the capillary action, thereby improving the problem of the decrease in the reliability of the battery module 120 caused by the electrolyte corroding the end cover of the battery module 120 and the problem of poor cycling performance of the battery module 120 caused by the reduction of the electrolyte.

[0089] In some embodiments, the groove extends to the side of the plastic part 124 facing the end cover 121. The two ends of the first liquid absorbing member 125 are respectively connected to the inner surface of the end cover 121 and the battery cell main body 123b. When the inverted battery module has a low electrolyte level, the first liquid absorbing member 125 can transfer the electrolyte towards the battery cell main body 123b.

[0090] Furthermore, the first liquid absorbing member 125 is embedded in the groove of the protruding part 1242, without occupying the space in the height direction of the battery module 120.

[0091] Furthermore, arranging the groove on the protruding part 1242 of the plastic part 124 to place the first liquid absorbing member 125 is beneficial for avoiding occupying extra space (such as height space) due to the arrangement of the first liquid absorbing member 125, having less influence on the original structure of the battery module 120, and also being beneficial for making the structure of the battery module 120 compact and realizing the miniaturization of the battery.

[0092] Combined Figures 4 to 9 As shown, the battery module 120 includes two battery cell assemblies 123 arranged side by side in the second direction, where the second direction is perpendicular to the first direction. The two protruding parts 1242 at both ends of the plastic part 124 in the first direction extend along the second direction at both ends of the plastic part 124. Among them, the two first liquid absorbing members 125 are arranged along the above-mentioned second direction. The two first liquid absorbing members 125 are respectively located in the middle of the two battery cell assemblies 123 in the second direction.

[0093] The first liquid-absorbing member 125 is disposed between the end cap 121 and the battery cell main body 123b to provide a path for transmitting the electrolyte; the first liquid-absorbing member 125 is embedded in the embedding groove of the plastic member 124, and the first liquid-absorbing member 125 is placed in the middle relative to the battery cell main body 123b. The number of the first liquid-absorbing members 125 is not limited to 2, and may be 1 or more.

[0094] In some embodiments, referring to Figures 10 to 15 , the first liquid-absorbing member 125 includes an embedded portion 1251 filled in the embedding groove. Optionally, one end of the embedded portion 1251 away from the battery cell main body 123b abuts against the bottom of the embedding groove, and one end of the embedded portion 1251 close to the battery cell main body 123b abuts against or is connected to the battery cell main body 123b. The embedding groove is open on the side facing the accommodation cavity, so that the embedded portion 1251 can guide the electrolyte toward the battery cell main body 123b through capillary action, which is beneficial to avoiding occupying extra space due to the arrangement of the first liquid-absorbing member 125 and having little influence on the original structure of the battery cell 120, and also beneficial to making the structure of the battery cell 120 compact and realizing the miniaturization of the battery.

[0095] In some embodiments, the first liquid-absorbing member 125 further includes an embedded portion 1251 filled in the embedding groove and a superimposed portion 1252 connected to the embedded portion 1251 and superimposed between the end face of the protruding portion 1242 facing the battery cell main body 123b and the battery cell main body 123b. The superimposed portion 1252 covers one end of the embedded portion 1251 close to the battery cell main body 123b and part or all of the end face of the protruding portion 1242 close to the battery cell main body 123b. It is beneficial to increase the contact area between the first liquid-absorbing member 125 and the battery cell main body 123b. The superimposed portion 1252 covers the end face of the protruding portion 1242 at both ends of the plastic member 124 facing the battery cell main body 123b, and the electrolyte can be transmitted to the battery cell main body 123b more evenly.

[0096] In some embodiments, referring to Figures 16 to 21 , the first liquid-absorbing member 125 includes an attaching portion 1253 attached to the inner surface of the plate-shaped portion 1241. The attaching portion 1253 can effectively absorb the electrolyte on the inner surface of the plate-shaped portion 1241, thereby improving the problems of the decrease in the reliability of the battery cell 120 caused by the electrolyte corroding the end cap of the battery cell 120 and the poor cycle performance of the battery cell 120 caused by the reduction of the electrolyte.

[0097] Referring to Figure 16 、 19And 21, in some embodiments, the attaching portion 1253 extends from the protruding portion 1242 through the through hole 1243 that allows the electrode terminal 121a, which is permitted to be connected to the tab 123a, to pass through the plate-like portion 1241. The attaching portion 1253 is disposed near the electrode terminal to guide the electrolyte near the electrode terminal 121a toward the battery cell main body 123b, which is beneficial to preventing the corrosion of the welding portion of the electrode terminal 121a by the electrolyte. Further, the problems of the reduction in the reliability of the battery cell 120 caused by the corrosion of the end cover of the battery cell 120 by the electrolyte and the poor cycle performance of the battery cell 120 caused by the reduction of the electrolyte are improved.

[0098] In some embodiments, the first liquid absorbing member 125 further includes a stacking portion 1252 that is connected to the attaching portion 1253 and stacked between the end face of the protruding portion 1242 facing the battery cell main body 123b and the battery cell main body 123b. The stacking portion 1252 covers one end of the embedded portion 1251 close to the battery cell main body 123b and part or all of the end face of the protruding portion 1242 close to the battery cell main body 123b. It is beneficial to increase the contact area between the first liquid absorbing member 125 and the battery cell main body 123b. The stacking portion 1252 covers the end faces of the protruding portions 1242 at both ends of the plastic part 124 facing the battery cell main body 123b, and the electrolyte can be more evenly transferred to the battery cell main body 123b.

[0099] In some embodiments, the first liquid absorbing member 125 further includes a connecting portion 1254 that connects the attaching portion 1253 and the stacking portion 1252. The connecting portion 1254 is attached to the side surface of the protruding portion 1242, see Figure 21 . It is beneficial to avoid occupying extra space due to the setting of the first liquid absorbing member 125, having less influence on the original structure of the battery cell 120, and also being beneficial to making the structure of the battery cell 120 compact and realizing the miniaturization of the battery.

[0100] See Figure 16 、 19 And 21, the first liquid absorbing member 125 includes a stacking portion 1252 covering the end face of the protruding portion 1242 facing the battery cell main body 123b, a connecting portion 1254 attached to the side surface of the protruding portion 1242 adjacent to one side of the through hole 1243, and an attaching portion 1253 attached to the inner surface of the plate-like portion 1241. The stacking portion 1252, the connecting portion 1254, and the attaching portion are connected in sequence and are arranged in a Z shape, which can effectively guide the electrolyte near the electrode terminal 121a toward the battery cell main body 123b, and improve the problems of the reduction in the reliability of the battery cell 120 caused by the corrosion of the end cover of the battery cell 120 by the electrolyte and the poor cycle performance of the battery cell 120 caused by the reduction of the electrolyte.

[0101] The first liquid absorption member 125 is attached to the outer surface of the plastic part, connecting the end face of the protruding part 1242 of the plastic part 124 facing the battery cell main body 123b and the inner surface of the sunken part, being attached to the surface of the plastic part, having sufficient contact area and simple assembly. Refer to Figure 16 and 19 .

[0102] In some embodiments, refer to Figures 22 to 25 , the tab 123a is bent from one side of the end face of one end of the battery cell main body 123b close to the plastic part 124 towards the middle. The battery cell 120 further includes a connecting member 127 covering the side of the bent tab 123a away from the battery cell main body 123b and connected to the tab 123a, and an electrode terminal 121a connected to the connecting member 127. The first end of the first liquid absorption member 125 is attached to the side of the connecting member 127 away from the tab 123a, and extends along the side of the bent tab 123a facing away from the battery cell main body 123b towards the battery cell main body 123b. In some embodiments, the side of the connecting member 127 away from the battery cell main body 123b is welded to the electrode terminal 121a.

[0103] The first liquid absorption member 125 is arranged near the electrode terminal to guide the electrolyte near the electrode terminal 121a towards the battery cell main body 123b, which is beneficial to preventing the corrosion of the welding part of the electrode terminal 121a by the electrolyte.

[0104] In some embodiments, the second end 125a of the first liquid absorption member 125 away from the connecting member 127 is attached to the side surface of the battery cell main body 123b to increase the contact area between the liquid absorption member and the battery cell main body. The first liquid absorption member 125 is attached to the outer surface of the tab 123a, and can guide the electrolyte at the welding mark of the electrode terminal 121a and at the tab 123a towards the battery cell main body 123b, improving the problems of the reduction of the reliability of the battery cell 120 caused by the corrosion of the end cover of the battery cell 120 by the electrolyte and the poor cycle performance of the battery cell 120 caused by the reduction of the electrolyte.

[0105] In some embodiments, the plastic part 124 covers the side of the connecting member 127 away from the battery cell assembly 123, and the side of the first liquid absorption member 125 away from the connecting member 127 is attached to the inner surface of the plate-shaped part 1241, so that the first liquid absorption member 125 absorbs the electrolyte above the plate-shaped part 1241 of the inverted battery cell 120, which is beneficial to preventing the problem of the electrolyte remaining on the plate-shaped part 1241.

[0106] In some embodiments, the battery cell further includes a second liquid absorbent member 126. The first end of the second liquid absorbent member 126 is attached to the side of the bent tab 123a facing the cell main body 123b and extends along the tab 123a towards the side of the cell main body 123b facing the plastic member 124. The second liquid absorbent member 126 can guide the electrolyte above the connecting member 127 of the inverted battery cell towards the cell main body 123b, which is beneficial to improving the problem of the electrolyte corroding the connection between the connecting member 127 and the tab 123a (such as the welding mark) and the connection between the connecting member 127 and the electrode terminal 121a (such as the welding mark). Furthermore, it improves the problem of the reliability reduction of the battery cell 120 caused by the electrolyte corroding the end cover of the battery cell 120 and the problem of poor cycling performance of the battery cell 120 caused by the reduction of the electrolyte.

[0107] In some embodiments, the second liquid absorbent member 126 extends to the side of the cell main body 123b, and the second end 126a of the second liquid absorbent member 126 away from the tab 123a is attached to the side of the cell main body 123b, and this side is located on one side of the end face of the cell main body 123b facing the plastic member 124. Refer to Figure 23 , to increase the contact area between the second liquid absorbent member 126 and the cell main body 123b, so as to quickly and efficiently transfer the electrolyte to the cell main body 123b. Of course, it can also extend to the edge of the end face of the end of the second liquid absorbent member 126 facing the plastic member 124 of the cell main body 123b.

[0108] The first liquid absorbent member 125 and the second liquid absorbent member 126 are respectively attached to the outer surface and the inner surface of the tab 123a, which can transfer the electrolyte and at the same time protect the tab 123a from contacting the housing 122 (aluminum shell) or the end cover 121.

[0109] In some embodiments, two cell assemblies 123 are arranged side by side, the tabs 123a of the two cell assemblies 123 are bent towards the junction of the two cell assemblies 123 respectively, and both sides of the connecting member 127 are connected to the tabs 123a of the two cell assemblies 123 respectively. The number of cell assemblies 123 is not limited to 2 bare cell structures, and the cell assemblies 123 are not limited to wound bare cells, and the same applies to laminated cells.

[0110] The assembly process of the battery cell 120 in this embodiment is as follows.

[0111] First, arrange two cell assemblies 123 side by side along the height direction of the cell assembly 123, and make the tabs 123a of the two cell assemblies 123 face each other. Then connect the tabs 123a of the two cell assemblies 123 with a connecting member 127. Then, stick the first liquid absorbent member 125 and the second liquid absorbent member 126 on both sides of the connecting member 127 and the tab 123a respectively. Refer to Figures 26 to 28。

[0112] Then, cover the plastic part 124 on the above-mentioned connecting part 127. The plastic part 124 can be provided with a first liquid-absorbing part 125 as shown in Figures 4 to 9 or as shown in Figures 10 to 15 provided with a first liquid-absorbing part 125 or as shown in Figures 16 to 21 provided with a first liquid-absorbing part 125. Refer to Figure 29 。

[0113] After that, after setting the end cap 121 and the electrode terminal 121a on the plastic part 124, bend the two battery cell assemblies 123 to the Figure 23 structure shown in, refer to Figure 30 。

[0114] The first liquid-absorbing part 125 is placed on the outer surface of the tab. The second liquid-absorbing part 126 is arranged on the surface of the innermost tab 123a to transfer the electrolyte at the welding mark position. The first liquid-absorbing part 125 is placed on the surface of the outer tab 123a and on the top surface of the connecting part 127 to transfer the electrolyte at the contact position between the connecting part 127 and the plastic part 124, as shown in Figure 23 。 Figure 24 The second end of the second liquid-absorbing part 126 may not be placed between the two battery cell assemblies 123, and it can be connected to the end face of the battery cell main body 123b.

[0115] The above are only exemplary embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing (122) having an opening at one end; An electrolyte is disposed in the housing (122); A battery cell assembly (123), comprising a battery cell body (123b) disposed in the shell (122) and a pole ear (123a) connected to the battery cell body (123b) and located at one end of the battery cell body (123b) close to the opening of the shell (122); a plastic part (124) covering the opening of the shell (122) to enclose, together with the shell (122), a containing cavity for containing the electrolyte and the battery cell assembly (123); the plastic part (124) comprising a plate-shaped portion (1241) covering the opening of the shell (122) and a protruding portion (1242) provided on the inner surface of the plate-shaped portion (1241) facing the shell (122); and A first liquid absorbing member (125) extends from the plastic member (124) toward the battery cell body (123b), wherein a distance between an end of the first liquid absorbing member (125) away from the battery cell body (123b) and the battery cell body (123b) is equal to or greater than a distance between an inner surface of the plate-shaped portion (1241) and the battery cell body (123b), The protruding portion (1242) is provided with an embedding groove connected to the accommodating cavity, the embedding groove extending from an end of the protruding portion (1242) close to the battery cell body (123b) toward the plate-like portion (1241), the depth of the embedding groove being greater than or equal to the height of the protruding portion (1242) protruding from the plate-like portion (1241), and the first liquid absorbing member (125) being embedded in the embedding groove. The first liquid absorbing member (125) comprises an embedded portion (1251) filled in the embedded groove and an overlapping portion (1252) connected to the embedded portion (1251) and overlapped between the end surface of the protruding portion (1242) facing the battery cell body (123b) and the battery cell body (123b), wherein the overlapping portion (1252) covers one end of the embedded portion (1251) close to the battery cell body (123b) and part or all of the end surface of the protruding portion (1242) close to the battery cell body (123b).

2. The battery cell according to claim 1, characterized in that: The plastic part (124) comprises a through hole (1243) allowing an electrode terminal (121a) connected to the electrode tab (123a) to pass through, two through holes (1243) are arranged along a first direction and are respectively located at two ends of the plastic part (124) along the first direction, and the first liquid absorbing part (125) is provided at an end of the plastic part (124) along the first direction.

3. The battery cell according to claim 1, characterized in that: It also comprises an end cover (121) which is arranged on a side of the plastic part (124) away from the battery cell assembly (123), and the embedding groove extends to a side of the plastic part (124) facing the end cover (121).

4. The battery cell according to claim 1, characterized in that: The first liquid-absorbing member (125) comprises an attachment portion (1253) attached to the inner surface of the plate-shaped portion (1241).

5. The battery cell according to claim 4, characterized in that: The overlapping portion (1252) is connected to the attaching portion (1253) and is overlapped between the end surface of the protruding portion (1242) facing the battery cell body (123b) and the battery cell body (123b), and the overlapping portion (1252) covers part or all of the end surface of the protruding portion (1242) close to the battery cell body (123b).

6. The battery cell according to claim 5, characterized in that: The first liquid-absorbing member (125) further comprises a connecting portion (1254) connecting the attaching portion (1253) and the overlapping portion (1252), wherein the connecting portion (1254) is attached to a side surface of the protruding portion (1242).

7. The battery cell according to claim 4, characterized in that: The attachment portion (1253) extends from the protruding portion (1242) toward a through hole (1243) of the plate-shaped portion (1241) that allows the electrode terminal (121a) connected to the electrode tab (123a) to pass through.

8. The battery cell according to claim 1, characterized in that: The pole ear (123a) is bent toward the middle from one side of the end surface of one end of the battery body (123b) close to the plastic part (124); the battery cell (120) further comprises a connector (127) which is covered on a side of the bent pole ear (123a) away from the battery body (123b) and connected to the pole ear (123a), and an electrode terminal (121a) connected to the connector (127); a first end of the first liquid absorbing member (125) is attached to a side of the connector (127) away from the pole ear (123a), and extends toward the battery body (123b) along a side of the bent pole ear (123a) facing away from the battery body (123b).

9. The battery cell according to claim 8, characterized in that: The second end (125a) of the first liquid absorbing member (125) away from the connecting member (127) is attached to the side surface of the battery core body (123b).

10. The battery cell according to claim 8, characterized in that: The plastic part (124) covers a side of the connecting part (127) away from the battery core assembly (123), and a side of the first liquid absorbent part (125) away from the connecting part (127) is attached to the inner surface of the plate-shaped part (1241).

11. The battery cell according to claim 8, characterized in that: It also includes a second liquid absorbing member (126), wherein a first end of the second liquid absorbing member (126) is attached to a side of the bent pole ear (123a) facing the battery cell body (123b), and extends along the pole ear (123a) toward a side of the battery cell body (123b) facing the plastic member (124).

12. The battery cell according to any one of claims 8 to 11, characterized in that: The two battery cell assemblies (123) are arranged side by side, the pole ears (123a) of the two battery cell assemblies (123) are respectively bent towards the junction of the two battery cell assemblies (123), and the two sides of the connecting member (127) are respectively connected to the pole ears (123a) of the two battery cell assemblies (123).

13. The battery cell according to claim 11, characterized in that: The second liquid absorbing member (126) extends to the side of the battery core body (123b), and the second end of the second liquid absorbing member (126) away from the pole ear (123a) is attached to the side of the battery core body (123b).

14. The battery cell according to claim 1, characterized in that: One end of the first liquid absorbing member (125) away from the plate-shaped portion (1241) abuts against or is connected to the battery core body (123b).

15. A battery pack, characterized in that: A battery cell comprising the battery cell according to any one of claims 1 to 14.

16. An electrical device, characterized in that: A battery pack comprising the battery pack of claim 15.

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